2018 5.0 XLT burning through oil - disable autostop/start?
09-15-2022, 04:44 PM
#1
2018 5.0 XLT burning through oil - disable autostop/start?
Hey Folks,
I've got a 2018 5.0 XLT that has been burning through a quart of oil every 600-700 miles. I'm well aware of the TSB for this, and I brought it to the dealer a couple weeks ago. They did the pcm update and gave me the longer dipstick. But I haven't driven it enough yet to see if the issue is fixed. But I read in a Facebook F150 group that disabling the autostop/start feature fixes the issue. So that's going to be my next step if the dealer trip didn't fix it.
My question for this forum is "does anyone know WHY disabling that feature mitigates or fixes the problem?" I suspect it has something to do with the manifold vacuum being stronger when the engine is stopped and started? And more frequent stopping/starting would just naturally cause more oil to be sucked into the combustion chamber through the various failure points? Am I guessing about right here? :-)
I've got a 2018 5.0 XLT that has been burning through a quart of oil every 600-700 miles. I'm well aware of the TSB for this, and I brought it to the dealer a couple weeks ago. They did the pcm update and gave me the longer dipstick. But I haven't driven it enough yet to see if the issue is fixed. But I read in a Facebook F150 group that disabling the autostop/start feature fixes the issue. So that's going to be my next step if the dealer trip didn't fix it.
My question for this forum is "does anyone know WHY disabling that feature mitigates or fixes the problem?" I suspect it has something to do with the manifold vacuum being stronger when the engine is stopped and started? And more frequent stopping/starting would just naturally cause more oil to be sucked into the combustion chamber through the various failure points? Am I guessing about right here? :-)
09-15-2022, 08:35 PM
#3
Well, there is a lot more to it all.
To your question, the Auto Stop/Start has nothing to do with oil passage. That comes from ignorance and guessing.
The TSB applied holds the Throttle body plate open a little more to reduce intake vacuum. It can have a small effect on fuel milage and draw on the PCV system.
The PCV valve change is of questionable value.
Dip stick change----- give me a break!.
The root cause is poor Piston Ring seal to the bore coating from 2018 on, oil gets by the bottom rings in rings pack x 8.
The blow-by is part of the issue as it causes excess oil mist back into the throttle body through the PCV path.
Bottom line is there are two paths the oil goes to get to the same place: the combustion chamber and out the exhaust.
After ring break-in, oil passage should subside to a very low level.
It's a long story to type.
I have been through it and now have a nice 5L.
To your question, the Auto Stop/Start has nothing to do with oil passage. That comes from ignorance and guessing.
The TSB applied holds the Throttle body plate open a little more to reduce intake vacuum. It can have a small effect on fuel milage and draw on the PCV system.
The PCV valve change is of questionable value.
Dip stick change----- give me a break!.
The root cause is poor Piston Ring seal to the bore coating from 2018 on, oil gets by the bottom rings in rings pack x 8.
The blow-by is part of the issue as it causes excess oil mist back into the throttle body through the PCV path.
Bottom line is there are two paths the oil goes to get to the same place: the combustion chamber and out the exhaust.
After ring break-in, oil passage should subside to a very low level.
It's a long story to type.
I have been through it and now have a nice 5L.
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DoubleFlush (09-16-2022)
09-16-2022, 08:07 AM
#4
Senior Member
Well, there is a lot more to it all.
To your question, the Auto Stop/Start has nothing to do with oil passage. That comes from ignorance and guessing.
The TSB applied holds the Throttle body plate open a little more to reduce intake vacuum. It can have a small effect on fuel milage and draw on the PCV system.
The PCV valve change is of questionable value.
Dip stick change----- give me a break!.
The root cause is poor Piston Ring seal to the bore coating from 2018 on, oil gets by the bottom rings in rings pack x 8.
The blow-by is part of the issue as it causes excess oil mist back into the throttle body through the PCV path.
Bottom line is there are two paths the oil goes to get to the same place: the combustion chamber and out the exhaust.
After ring break-in, oil passage should subside to a very low level.
It's a long story to type.
I have been through it and now have a nice 5L.
To your question, the Auto Stop/Start has nothing to do with oil passage. That comes from ignorance and guessing.
The TSB applied holds the Throttle body plate open a little more to reduce intake vacuum. It can have a small effect on fuel milage and draw on the PCV system.
The PCV valve change is of questionable value.
Dip stick change----- give me a break!.
The root cause is poor Piston Ring seal to the bore coating from 2018 on, oil gets by the bottom rings in rings pack x 8.
The blow-by is part of the issue as it causes excess oil mist back into the throttle body through the PCV path.
Bottom line is there are two paths the oil goes to get to the same place: the combustion chamber and out the exhaust.
After ring break-in, oil passage should subside to a very low level.
It's a long story to type.
I have been through it and now have a nice 5L.
I have the original PCV valve saved and the newer one with the cross hatch. Blowing air through both with my mouth, I could sense no difference.
The other is a question. Do you still think that the 8.8 specified quart capacity is an overfill?
09-16-2022, 08:54 AM
#5
mine is very sensitive to viscosity, the difference between a quart over and oci and half a quart over an oci, is simply the range in which a particular oil manf. choose to set their viscosity. one 5w-20 to the next will vary and i can see it in the oil usage. running royal purple right now. seems to be on the higher end.
09-23-2022, 03:50 PM
#6
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I have the same issue with my 2018. They did the TSB with no luck....still burning oil At my next oil change, they will begin the process of monitoring the oil consumption over time/miles to make the formal determination if it exceeds Ford's specification. Would be interesting to see if the TSB fixes your issue.